Effect of Cannabis sativa L. extracts, phytocannabinoids and their acetylated derivates on the SHSY-5Y neuroblastoma cells' viability and caspases 3/7 activation.

BACKGROUND: There is a need for novel treatments for neuroblastoma, despite the emergence of new biological and immune treatments, since refractory pediatric neuroblastoma is still a medical challenge. Phyto cannabinoids and their hemisynthetic derivatives have shown evidence supporting their anticancer potential. The aim of this research was to examine Phytocannabinoids or hemisynthetic cannabinoids, which reduce the SHSY-5Y, neuroblastoma cell line's viability. METHODS: Hexane and acetyl acetate extracts were produced starting with Cannabis sativa L. as raw material, then, 9-tetrahidrocannabinol, its acid counterpart and CBN were isolated. In addition, acetylated derivatives of THC and CBN were synthesized. The identification and purity of the chemicals was determined by High Performance Liquid Chromatography and 1H y 13C Magnetic Nuclear Resonance. Then, the capacity to affect the viability of SHSY-5Y, a neuroblastoma cell line, was examined using the resazurin method. Finally, to gain insight into the mechanism of action of the extracts, phytocannabinoids and acetylated derivatives on the examined cells, a caspase 3/7 determination was performed on cells exposed to these compounds. RESULTS: The structure and purity of the isolated compounds was demonstrated. The extracts, the phytocannabinoids and their acetylated counterparts inhibited the viability of the SHSY 5Y cells, being CBN the most potent of all the tested molecules with an inhibitory concentration of 50 percent of 9.5 µM. CONCLUSION: Each of the evaluated molecules exhibited the capacity to activate caspases 3/7, indicating that at least in part, the cytotoxicity of the tested phytocannabinoids and their hemi-synthetic derivatives is mediated by apoptosis.

Organoides de origen humano como modelo fisiopatológico de evaluación terapéutica de fármacos en COVID-19 / Organoids as a physiopathology model and therapeutic drug evaluation tool in COVID-19

Introducción: La pandemia causada por SARS-CoV-2 ha impactado al mundo gravemente en diversos ámbitos y con ello ha surgido la necesidad de contar con herramientas con mayor relevancia fisiológica para investigar patologías complejas como el COVID-19. Los organoides son un modelo experimental con características únicas como la capacidad de autoformar una estructura tridimensional utilizando células en cultivo. Sobre esta base, surge la siguiente pregunta ¿son los organoides un modelo experimental factible para reflejar la fisiopatología del COVID-19 y evaluar la eficacia de fármacos que limiten su progresión? Metodología: Para abordar esta interrogante, esta revisión plantea el analizar la validez de los organoides como modelo experimental y verificar su utilidad en la evaluación de fármacos para el COVID-19. Para cumplir estos objetivos se realizó una revisión sistemática cualitativa de la literatura, a través de una búsqueda en PubMed con el término 'COVID-19 and stem cells and organoids' y también en un número especial de la revista Cell. Resultados: Se organizaron los resultados relevantes por sistema fisiológico y en la evaluación de fármacos. Los organoides más empleados para estudios de COVID-19 correspondieron a tejido respiratorio, nervioso y digestivo. Algunos resultados encontrados en la revisión fueron similares a aquellos obtenidos a partir de tejidos de pacientes COVID-19 o autopsias, encontrándose hallazgos relevantes como la posible disrupción de la barrera epitelial del sistema nervioso por infección del plexo coroideo. También se logró observar efectividad de fármacos que posteriormente pasaron a ser aprobados y utilizados exitosamente en pacientes. Conclusión: Los organoides se pueden componer a partir de diferentes tipos celulares y bajo diferentes protocolos experimentales, siendo relevante la lectura crítica de los artículos científicos para decidir si sus resultados son extrapolables a la fisiopatología de la enfermedad.

Introduction: The pandemic caused by SARS-CoV-2 has impacted the world severely in several aspects and has created the need for research tools to study the COVID-19 disease. Organoids are experimental models with unique characteristics, like the ability to self-assemble in a tridimensional structure. Based on this, the following question arises: are organoids an experimental model suitable to reflect the physiopathology of COVID-19 and to allow the evaluation of the efficacy of drugs that limit its progression? Methods: To approach this question, this review aimed to analyze the validity of organoids as an experimental model and verify their utility in COVID-19 drug evaluation. To resolve these objectives, a qualitative systematic review was done through a PubMed search with the terms 'COVID-19 and stem cells and organoids' and on a special issue of the Cell Journal. Results: The results were organized by physiologic system and therapeutic drug evaluation. The most utilized tissues for the COVID-19 study were respiratory, nervous, and digestive. Some results found in the review were like those obtained from COVID-19 patient tissue or autopsies, finding some relevant discoveries like the possibility of the choroid plexus disruption in the nervous system caused by the infection. Efficacy was also observed in approved drugs and used later in patients successfully. Conclusion: Organoids might be composed starting with different cell types and under a variety of experimental protocols, being relevant the critical reading of the scientific literature to decide whether their results can be extrapolated to the pathophysiology of the disease

The Antiproliferative Activity of a Mixture of Peptide and Oligosaccharide Extracts Obtained from Defatted Rapeseed Meal on Breast Cancer Cells and Human Fibroblasts.

Oligosaccharide and peptide extracts obtained separately from defatted rapeseed meal (DRM) have shown antiproliferative activities on the MCF-7 breast cancer cell line. However, oligosaccharide extracts were not tested on human fibroblasts and have low yields. The objective of the present study was to combine two antiproliferative extracts, the peptides and oligosaccharides, that were obtained independently with commercial enzymes from DRM, allowing improvement of the mass yield and antiproliferative activity. The DRM was solubilized in an alkaline medium to obtain an insoluble meal residue (IMR) and an alkaline extract (RAE). To produce the oligosaccharide extract from IMR, three enzymes and different enzyme/substrate ratios were used. The oligosaccharide extract (molecular weight <30 kDa) recovered with the commercial enzyme. Endogalacturonase showed an 80% inhibition on MCF-7 cells at 20 mg/mL. The combination of this oligosaccharide extract with the peptide extract (obtained with Alkalase 2.4 L from a RAE at 10 mg/mL) inhibited 84.3% of MCF-7 cells proliferation at a concentration of 20 mg/mL, exhibiting no cytotoxic effects on fibroblasts. The mass yield of the extract pool was 27.07% (based on initial DRM). It can be concluded that a mixture of antiproliferative extracts was produced from DRM which was selective against MCF-7 cells.

Involvement of Inflammation and Its Resolution in Disease and Therapeutics.

Inflammation plays a critical role in the response to and survival from injuries and/or infections. It occurs in two phases: initiation and resolution; however, when these events do not resolve and persist over time, the inflammatory response becomes chronic, prompting diseases that affect several systems and organs, such as the vasculature and the skin. Here, we reviewed inflammation that occurs in selected infectious and sterile pathologies. Thus, the immune processes induced by bacterial sepsis as well as T. cruzi and SARS-CoV-2 infections are shown. In addition, vaccine adjuvants as well as atherosclerosis are revised as examples of sterile-mediated inflammation. An example of the consequences of a lack of inflammation resolution is given through the revision of wound healing and chronic wounds. Then, we revised the resolution of the latter through advanced therapies represented by cell therapy and tissue engineering approaches, showing how they contribute to control chronic inflammation and therefore wound healing. Finally, new pharmacological insights into the management of chronic inflammation addressing the resolution of inflammation based on pro-resolving mediators, such as lipoxin, maresin, and resolvins, examining their biosynthesis, biological properties, and pharmacokinetic and pharmaceuticals limitations, are given. We conclude that resolution pharmacology and advanced therapies are promising tools to restore the inflammation homeostasis.

QSAR-driven synthesis of antiproliferative chalcones against SH-SY5Y cancer cells: Design, biological evaluation, and redesign.

Neuroblastoma is one of the most frequent types of cancer found in infants, and traditional chemotherapy has limited efficacy against this pathology. Thus, the development of new compounds with higher activity and selectivity than traditional drugs is a current challenge in medicinal chemistry research. In this study, we report the synthesis of 21 chalcones with antiproliferative activity and selectivity against the neuroblastoma cell line SH-SY5Y. Then, we developed three-dimensional quantitative structure-activity relationship models (comparative molecular field analysis and comparative molecular similarity index analysis) with high-quality statistical values (q2 > 0.7; r2 > 0.8; r2 pred > 0.7), using IC50 and selectivity index (SI) data as dependent variables. With the information derived from these theoretical models, we designed and synthesized 16 new molecules to prove their consistency, finding good antiproliferative activity against SH-SY5Y cells on these derivatives, with three of them showing higher SI than the referential drugs 5-fluorouracil and cisplatin, displaying also a proapoptotic effect comparable to these drugs, as proven by measuring their effects on executor caspases 3/7 activity induction, Bcl-2/Bax messenger RNA levels alteration, and DNA fragmentation promotion.

Inhibition of Caco-2 and MCF-7 cancer cells using chalcones: synthesis, biological evaluation and computational study.

Cancer is the second death cause worldwide, with breast and colon cancer among the most prevalent types. Traditional treatment strategies have several side effects that inspire the development of novel anticancer agents derived from natural sources, like chalcone derivatives. For this investigation, twenty-three chalcones (4a-w) were synthesized and evaluated as antiproliferative agents against MCF-7 and Caco-2 cells, finding three and two compounds with similar or higher antiproliferative activity than daunorubicin, while only two chalcones showed better selectivity indexes than daunorubicin on MCF-7. From these results, we developed good-performance QSAR models (r > 0.850, q2>0.650), finding several structural features that could modify chalcone activity and selectivity. According to these models, chalcones 4w and 4t have high potency and selectivity against Caco-2 and MCF-7, respectively, which make them attractive candidates for hit-to-lead development of ROS-independent pro apoptotic agents.

Alfabetización estadística y comunicación de riesgo para la vacunación contra la COVID-19: una revisión de alcance

[RESUMEN]. Objetivo. Describir el papel que desempeñan la alfabetización estadística y la correcta comunicación de riesgo en las estrategias de comunicación relacionadas con la vacunación contra la COVID-19. Métodos. Se realizó una revisión de alcance en enero del 2021, con las palabras clave “ statistical literacy ”, “ risk communication”, “health communication ” y “ pandemic ” en las bases de datos de la Biblioteca Virtual en Salud de la Organización Panamericana de la Salud, PubMed, Web of Science, EBSCO y Google Académico. No se aplicaron filtros para fechas, idioma o tipos de publicación. Resultados. De los 87 artículos identificados, cuatro cumplieron con los criterios de inclusión. Se recono-cieron cuatro mensajes principales que relacionan la alfabetización estadística y la comunicación de riesgo: 1) la comunicación de riesgo y el nivel de alfabetización estadística afectan a la toma de decisión individual y colectiva, 2) la comunicación de la incertidumbre debe incluir lo que se sabe y no se sabe respecto a las estadísticas y los riesgos, 3) el uso de gráficos y visualizaciones es clave para informar apropiadamente a la población y 4) deben utilizarse diferentes formatos para mejorar la comunicación, siempre ajustados al nivel de alfabetización estadística de la población. Conclusiones. La alfabetización estadística desempeña un papel clave en la comunicación de los riesgos relacionados con la salud en general y la vacunación contra la COVID-19 en particular. En situaciones de emergencia sanitaria, la correcta comunicación de riesgo y de la incertidumbre asociada debe ser clara, transparente y oportuna.

[ABSTRACT]. Objective. To describe the role of statistical literacy and proper risk communication in communication strate-gies related to COVID-19 vaccination.Methods. A scoping review was carried out in January 2021, with the keywords “statistical literacy,” “risk com-munication,” “health communication,” and “pandemic,” in the Pan American Health Organization Virtual Health Library, PubMed, Web of Science, EBSCO, and Google Scholar databases. No filters were applied for dates, language, or publication type.Results. Of the 87 articles identified, four met the inclusion criteria. Four main messages were recognized that relate statistical literacy and risk communication: 1) risk communication and statistical literacy level affect indi-vidual and collective decision-making; 2) communication of uncertainty should include what is known and not known with regard to statistics and risks; 3) the use of graphics and visuals is key to appropriately informing the population; and 4) different formats should be used to improve communication, always adjusted to the population’s statistical literacy level.Conclusions. Statistical literacy plays a key role in communicating risks related to health in general and COVID-19 vaccination in particular. In health emergencies, proper communication of risk and associated uncertainty should be clear, transparent, and timely.

[RESUMO]. Objetivo. Descrever o papel da literacia estatística e da comunicação correta de riscos nas estratégias de comunicação relacionadas à vacinação contra a COVID-19.Métodos. Em janeiro de 2021, foi realizada uma revisão de escopo com as palavras-chave “statistical lite-racy”, “risk communication”, “health communication” e “pandemic” nos bancos de dados da Biblioteca Virtual em Saúde da Organização Pan-Americana da Saúde, PubMed, Web of Science, EBSCO e Google Scholar. Não foi aplicado filtro de data, idioma ou tipo de publicação.Resultados. Dos 87 artigos identificados, quatro atenderam aos critérios de inclusão. Foram reconhecidas quatro mensagens principais relacionadas à literacia estatística e à comunicação de risco: 1) a comunicação de risco e o nível de literacia estatística afetam a tomada de decisão individual e coletiva; 2) a comunicação da incerteza deve incluir o que é conhecido e desconhecido sobre estatísticas e riscos; 3) o uso de gráficos e visualizações é fundamental para informar adequadamente a população; e 4) devem ser usados diferentes formatos para melhorar a comunicação, sempre ajustados ao nível de literacia estatística da população.Conclusões. A literacia estatística desempenha um papel fundamental na comunicação dos riscos relaciona-dos à saúde em geral e à vacinação contra a COVID-19 em particular. Em situações de emergência de saúde, a comunicação correta do risco e da incerteza a ele associada deve ser clara, transparente e oportuna.

Natural isoflavonoids in invasive cancer therapy: From bench to bedside.

Cancer is a public health problem worldwide, and one of the crucial steps within tumor progression is the invasion and metastasis of cancer cells, which are directly related to cancer-associated deaths in patients. Recognizing the molecular markers involved in invasion and metastasis is essential to find targeted therapies in cancer. Interestingly, about 50% of the discovered drugs used in chemotherapy have been obtained from natural sources such as plants, including isoflavonoids. Until now, most drugs are used in chemotherapy targeting proliferation and apoptosis-related molecules. Here, we review recent studies about the effect of isoflavonoids on molecular targets and signaling pathways related to invasion and metastasis in cancer cell cultures, in vivo assays, and clinical trials. This review also reports that glycitein, daidzein, and genistein are the isoflavonoids most studied in preclinical and clinical trials and displayed the most anticancer activity targeting invasion-related proteins such as MMP-2 and MMP-9 and also EMT-associated proteins. Therefore, the diversity of isoflavonoids is promising molecules to be used as chemotherapeutic in invasive cancer. In the future, more clinical trials are needed to validate the effectiveness of the various natural isoflavonoids in the treatment of invasive cancer.

Antiproliferative Rapeseed Defatted Meal Protein and Their Hydrolysates on MCF-7 Breast Cancer Cells and Human Fibroblasts.

Defatted rapeseed meal (DRM) is a sub-valorized agro-industrial by-product, with a high protein content whose peptides could have potential anticancer activity against cancer cell lines. The objective of the present study is to obtain an enzymatic hydrolysate of rapeseed protein that inhibits proliferation on a breast cancer cell line (MCF-7), but not healthy human fibroblast cells. The DRM was solubilized in an alkaline medium to obtain an alkaline rapeseed extract (RAE). Acid precipitation of the proteins contained in RAE recovered a rapeseed protein isolate (RPI). To produce protein hydrolysates, two alkaline protease and different enzyme/substrate ratios were used. All the protein hydrolysates showed antiproliferative activity on MCF-7 cells. However, only the hydrolysate recovered from the enzymatic hydrolysis of RPI (Degree of hydrolysis (DH ) between 8.5 and 9% (DH1)) did not affect human fibroblast cells, inhibiting 83.9% of MCF-7 cells' proliferation and showing a mass yield of 22.9% (based on the initial DRM). The SDS-PAGE gel revealed that DH1 was composed mainly of 10 kDa peptides and, to a lesser extent, 5 and 2 kDa. It is concluded that DH1 is a promising peptide extract for future research as a putative anti-breast cancer agent.

Restraint of Human Skin Fibroblast Motility, Migration, and Cell Surface Actin Dynamics, by Pannexin 1 and P2X7 Receptor Signaling.

Wound healing is a dynamic process required to maintain skin integrity and which relies on the precise migration of different cell types. A key molecule that regulates this process is ATP. However, the mechanisms involved in extracellular ATP management are poorly understood, particularly in the human dermis. Here, we explore the role, in human fibroblast migration during wound healing, of Pannexin 1 channels and their relationship with purinergic signals and in vivo cell surface filamentous actin dynamics. Using siRNA against Panx isoforms and different Panx1 channel inhibitors, we demonstrate in cultured human dermal fibroblasts that the absence or inhibition of Panx1 channels accelerates cell migration, increases single-cell motility, and promotes actin redistribution. These changes occur through a mechanism that involves the release of ATP to the extracellular space through a Panx1-dependent mechanism and the activation of the purinergic receptor P2X7. Together, these findings point to a pivotal role of Panx1 channels in skin fibroblast migration and suggest that these channels could be a useful pharmacological target to promote damaged skin healing.

Epanorin, a lichen secondary metabolite, inhibits proliferation of MCF-7 breast cancer cells.

BACKGROUND: Epanorin (EP) is a secondary metabolite of the Acarospora lichenic species. EP has been found in lichenic extracts with antimicrobial activity, and UV-absorption properties have been described for closely related molecules; however, its antiproliferative activity in cancer cells has not yet been explored. It has been hypothesized that EP inhibits cancer cell growth. MCF-7 breast cancer cells, normal fibroblasts, and the non-transformed HEK-293 cell line were exposed to increasing concentrations of EP, and proliferation was assessed by the sulforhodamine-B assay. RESULTS: MCF-7 cells exposed to EP were examined for cell cycle progression using flow cytometry, and DNA fragmentation was examined using the TUNEL assay. In addition, EP's mutagenic activity was assessed using the Salmonella typhimurium reverse mutation assay. The data showed that EP inhibits proliferation of MCF-7 cells, and it induces cell cycle arrest in G0/G1 through a DNA fragmentation-independent mechanism. Furthermore, EP's lack of overt cytotoxicity in the normal cell line HEK-293 and human fibroblasts in cell culture is supported by the absence of mutagenic activity of EP. CONCLUSION: EP emerges as a suitable molecule for further studies as a potential antineoplastic agent.

Epanorin, a lichen secondary metabolite, inhibits proliferation of MCF-7 breast cancer cells

BACKGROUND: Epanorin (EP) is a secondary metabolite of the Acarospora lichenic species. EP has been found in lichenic extracts with antimicrobial activity, and UV-absorption properties have been described for closely related molecules; however, its antiproliferative activity in cancer cells has not yet been explored. It has been hypothesized that EP inhibits cancer cell growth. MCF-7 breast cancer cells, normal fibroblasts, and the non-transformed HEK-293 cell line were exposed to increasing concentrations of EP, and proliferation was assessed by the sulforhodamine-B assay. RESULTS: MCF-7 cells exposed to EP were examined for cell cycle progression using flow cytometry, and DNA fragmentation was examined using the TUNEL assay. In addition, EP's mutagenic activity was assessed using the Salmonella typhimurium reverse mutation assay. The data showed that EP inhibits proliferation of MCF-7 cells, and it induces cell cycle arrest in G0/G1 through a DNA fragmentation-independent mechanism. Furthermore, EP's lack of overt cytotoxicity in the normal cell line HEK-293 and human fibroblasts in cell culture is supported by the absence of mutagenic activity of EP. CONCLUSION: EP emerges as a suitable molecule for further studies as a potential antineoplastic agent.

Design of a hybrid biomaterial for tissue engineering: Biopolymer-scaffold integrated with an autologous hydrogel carrying mesenchymal stem-cells.

Biologically active biomaterials as biopolymers and hydrogels have been used in medical applications providing favorable results in tissue engineering. In this research, a wound dressing device was designed by integration of an autologous clot hydrogel carrying mesenchymal stem-cells onto a biopolymeric scaffold. This hybrid biomaterial was tested in-vitro and in-vivo, and used in a human clinical case. The biopolymeric scaffold was made with gelatin, chitosan and hyaluronic acid, using a freeze-drying method. The scaffold was a porous material which was designed evaluating both physical properties (glass transition, melting temperature and pore size) and biological properties (cell viability and fibronectin expression). Two types of chitosan (120 and 300kDa) were used to manufacture the scaffold, being the high molecular weight the most biologically active and stable after sterilization with gamma irradiation (25kGy). A clot hydrogel was formulated with autologous plasma and calcium chloride, using an approach based on design of experiments. The optimum hydrogel was used to incorporate cells onto the porous scaffold, forming a wound dressing biomaterial. The wound dressing device was firstly tested in-vitro using human cells, and then, its biosecurity was evaluated in-vivo using a rabbit model. The in-vitro results showed high cell viability after one week (99.5%), high mitotic index (19.8%) and high fibronectin expression. The in-vivo application to rabbits showed adequate biodegradability capacity (between 1 and 2weeks), and the histological evaluation confirmed absence of rejection signs and reepithelization on the wound zone. Finally, the wound dressing biomaterial was used in a single human case to implant autologous cells on a skin surgery. The medical examination indicated high biocompatibility, partial biodegradation at one week, early regeneration capacity at 4weeks and absence of rejection signs.

TGFß3 secretion by three-dimensional cultures of human dental apical papilla mesenchymal stem cells.

Mesenchymal stem cells (MSCs) can be isolated from dental tissues, such as pulp and periodontal ligament; the dental apical papilla (DAP) is a less-studied MSC source. These dental-derived MSCs are of great interest because of their potential as an accessible source for cell-based therapies and tissue-engineering (TE) approaches. Much of the interest regarding MSCs relies on the trophic-mediated repair and regenerative effects observed when they are implanted. TGFß3 is a key growth factor involved in tissue regeneration and scarless tissue repair. We hypothesized that human DAP-derived MSCs (hSCAPs) can produce and secrete TGFß3 in response to micro-environmental cues. For this, we encapsulated hSCAPs in different types of matrix and evaluated TGFß3 secretion. We found that dynamic changes of cell-matrix interactions and mechanical stress that cells sense during the transition from a monolayer culture (two-dimensional, 2D) towards a three-dimensional (3D) culture condition, rather than the different chemical composition of the scaffolds, may trigger the TGFß3 secretion, while monolayer cultures showed almost 10-fold less secretion of TGFß3. The study of these interactions is provided as a cornerstone in designing future strategies in TE and cell therapy that are more efficient and effective for repair/regeneration of damaged tissues. Copyright © 2015 John Wiley & Sons, Ltd.

Edible Scaffolds Based on Non-Mammalian Biopolymers for Myoblast Growth.

In vitro meat has recently emerged as a new concept in food biotechnology. Methods to produce in vitro meat generally involve the growth of muscle cells that are cultured on scaffolds using bioreactors. Suitable scaffold design and manufacture are critical to downstream culture and meat production. Most current scaffolds are based on mammalian-derived biomaterials, the use of which is counter to the desire to obviate mammal slaughter in artificial meat production. Consequently, most of the knowledge is related to the design and control of scaffold properties based on these mammalian-sourced materials. To address this, four different scaffold materials were formulated using non-mammalian sources, namely, salmon gelatin, alginate, and additives including gelling agents and plasticizers. The scaffolds were produced using a freeze-drying process, and the physical, mechanical, and biological properties of the scaffolds were evaluated. The most promising scaffolds were produced from salmon gelatin, alginate, agarose, and glycerol, which exhibited relatively large pore sizes (~200 µm diameter) and biocompatibility, permitting myoblast cell adhesion (~40%) and growth (~24 h duplication time). The biodegradation profiles of the scaffolds were followed, and were observed to be less than 25% after 4 weeks. The scaffolds enabled suitable myogenic response, with high cell proliferation, viability, and adequate cell distribution throughout. This system composed of non-mammalian edible scaffold material and muscle-cells is promising for the production of in vitro meat.

Designing a gelatin/chitosan/hyaluronic acid biopolymer using a thermophysical approach for use in tissue engineering.

Cell culture on biopolymeric scaffolds has provided treatments for tissue engineering. Biopolymeric mixtures based on gelatin (Ge), chitosan (Ch) and hyaluronic acid (Ha) have been used to make scaffolds for wound healing. Thermal and physical properties of scaffolds prepared with Ge, Ch and Ha were characterized. Thermal characterization was made by using differential scanning calorimetry (DSC), and physical characterization by gas pycnometry and scanning electron microscopy. The effects of Ge content and cross-linking on thermophysical properties were evaluated by means of a factorial experiment design (central composite face centered). Gelatin content was the main factor that affects the thermophysical properties (microstructure and thermal transitions) of the scaffold. The effect of Ge content of the scaffolds for tissue engineering was studied by seeding skin cells on the biopolymers. The cell attachment was not significantly modified at different Ge contents; however, the cell growth rate increased linearly with the decrease of the Ge content. This relationship together with the thermophysical characterization may be used to design scaffolds for tissue engineering.

Improvement of human skin cell growth by radiation-induced modifications of a Ge/Ch/Ha scaffold.

Gelatin-/chitosan-/hyaluronan-based biomaterials are used in tissue engineering as cell scaffolds. Three gamma radiation doses (1, 10 and 25 kGy) were applied to scaffolds for sterilization. Microstructural changes of the irradiated polymers were evaluated by using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). A dose of 25 kGy produced a rough microstructure with a reduction of the porosity (from 99 to 96 %) and pore size (from 160 to 123 µm). Radiation also modified the glass transition temperature between 31.2 and 42.1 °C (1 and 25 kGy respectively). Human skin cells cultivated on scaffolds irradiated with 10 and 25 kGy proliferated at 48 h and secreted transforming growth factor ß3 (TGF-ß3). Doses of 0 kGy (non-irradiated) or 1 kGy did not stimulate TGF-ß3 secretion or cell proliferation. The specific growth rate and lactate production increased proportionally to radiation dose. The use of an appropriate radiation dose improves the cell scaffold properties of biomaterials.

Effect of the standardized Cimicifuga foetida extract on Hsp 27 expression in the MCF-7 cell line.

Cimicifuga foetida, an Asian Cimicifuga species, has been employed as a cooling and detoxification agent in traditional Chinese medicine since ancient times. For this herb, two cycloartane triterpene glycosides isolated from the rhizomes have demonstrated cytotoxicity on rat tumor and human cancer cell lines. Since human Hsp27 is increased in various human cancers and exhibits cytoprotective activity that affects tumorigenesis and the susceptibility of tumours to cancer treatment, the purpose of this research was to study the expression of this protein in MCF-7 breast cancer cells. To accomplish this aim, MCF-7 cells were exposed to different concentrations of Cimicifuga foetida extract showing a reduction in cell number measured by the sulforhodamine assay. In addition, the expression of Hsp-27 mRNA detected by RT-PCR and Hsp-27 protein detected by immnofluorescence was present in all conditions, except when using the highest concentration of Cimicifuga foetida extract (2,000 jig /L). We conclude that Hsp 27 expression at 2,000 jig /L Cimicifuga foetida extract is diminished. This is the first report showing the Hsp-27 expression after exposure to Cimicifuga foetida extract in MCF-7 cells.

Effect of the standardized Cimicifuga foetida extract on Hsp 27 expression in the MCF-7 cell line

Cimicifuga foetida, an Asian Cimicifuga species, has been employed as a cooling and detoxification agent in traditional Chinese medicine since ancient times. For this herb, two cycloartane triterpene glycosides isolated from the rhizomes have demonstrated cytotoxicity on rat tumor and human cancer cell lines. Since human Hsp27 is increased in various human cancers and exhibits cytoprotective activity that affects tumorigenesis and the susceptibility of tumours to cancer treatment, the purpose of this research was to study the expression of this protein in MCF-7 breast cancer cells. To accomplish this aim, MCF-7 cells were exposed to different concentrations of Cimicifuga foetida extract showing a reduction in cell number measured by the sulforhodamine assay. In addition, the expression of Hsp-27 mRNA detected by RT-PCR and Hsp-27 protein detected by immnofluorescence was present in all conditions, except when using the highest concentration of Cimicifuga foetida extract (2,000 jig /L). We conclude that Hsp 27 expression at 2,000 jig /L Cimicifuga foetida extract is diminished. This is the first report showing the Hsp-27 expression after exposure to Cimicifuga foetida extract in MCF-7 cells.